Discriminating proximity ordnance fuze

ABSTRACT

A mechanical fuze for aerial ordnance devices having an extendable probe mounting on its nose and an actuator nonresponsive to the presence of foliage and responsive only to target impact. A safety and arming mechanism is provided having a double-locked rotor which rotates to an armed position only after an electrical signal has been delivered to the fuze and after the probe has been extended. A clamp is provided which locks and rigidifies the probe in its extended position.

United States Patent Inventor Cecil L. Duncan Silver Spring, Md. Appl. No. 821,174 Filed May 2, 1969 Patented Sept. 14, 1971 Assignee The United States 01 America as represented by the Secretary of the Navy DISCRIMINATING PROXIMITY ORDNANCE FUZE 10 Claims, 7 Drawing Figs.

[56] References Cited UNITED STATES PATENTS 2.023.938 12/1935 Savani 102/81 2.731892 3/1956 Dalton et a1. 102/81 2989923 6/1961 Rodriquez Villa et al. 102/81 X 2.998.770 9/1961 Bernard 102/81 X Primary ExaminerBenjamin A. Borchelt Assistant Examiner-Thomas H. Webb Atl0rneysR. S. Sciascia and J. A. Cooke ABSTRACT: A mechanical fuze for aerial ordnance devices having an extendable probe mounting on its nose and an actuator nonresponsive to the presence of foliage and responsive US. Cl 102/81, only to target impact. A safety and arming mechanism is pro- 102/78 vided having a double-locked rotor which rotates to an armed lnt.Cl F42c l/14, position only after an electrical signal has been delivered to F42c 13/00, F42c 15/40 the fuze and after the probe has been extended. A clamp is Field of Search 102/76, 78, provided which locks and rigidities the probe in its extended 81 position.

/08 I07 60 a4 a/ 79 79 a? 6 I04 7 /o L /OO /0/ i 1& 5 /02 H5 75 2 l2/ 9 a 23 2? //9 PATENTED SEP14|97I 350 13 7 SHEET 1 OF 5 Fig. la

INVENTOR Cecll L. Duncan .0. 1 44%; 8 ATT EY Pmminssmmn 3,604,357

SHEET 2 OF 5 Fig. lb /0 PATENTEUSEFMIHYI 3,604,357

sum 3 or s Fig. lc

PATENTEUSEP14 ml SHEET 5 OF 5 Fig.

DISCRIMINATING PROXIMITY ORDNANCE FUZE BACKGROUND OF THE INVENTION This invention relates generally to ordnance fuzes and more particularly to a discriminating mechanical proximity fuze for an aerial ordnance device.

A widespread problem encountered with fuzes for aerial ordnance devices such as bombs, rockets, projectiles and the like, is the premature detonation of the devices due to impact with the dense foliage above the intended target area. If the actuating mechanism of the fuze of the ordnance device is sufficiently sensitive to function on impact with a target composed of a soft material, such as loose dirt, mud, sand or water then it tends also to function as the ordnance device passes through the dense foliage that covers some targets, causing premature detonation. The problem is compounded where the foliage is at a great height thereby resulting in an ineffectual detonation high above the target. On the other hand, if the actuatirig mechanism were designed to be insensitive to the impact delivered during passage through the foliage over the target area, then the mechanism tends to be insensitive to impact with such soft targets thus rendering the ordnance device effective only against a hard target, such as a solid surface.

A long felt need has existed, therefore, for a reliable mechanical fuze that will be unaffected by the presence of dense foliage and will positively function on impact with a soft as well as a hard target.

A need also has existed for a mechanical fuze which will affect detonation of an ordnance device at a short distance above the ground. In some instances when the actuating mechanism is mounted on the nose of the ordnance device it may become partially or completely embedded in soft ground before effectiveness of the explosive burst of the ordnance device. Even when detonation is achieved at the instant of contact the ordnance device is at ground level and the effective destructiveness of the burst is far less than it might be at a proximate distance above the ground.

This problem has been the subject of much attention and the proposed solutions have been many and varied. Electronic proximity type fuzes are a well known approach to the problem. In mechanical fuzes, various extensions designed to protrude ahead of the ordnance device and sense the presence of the ground have been employed. One approach of particular interest is the use of a volute extension spring which is stored in a telescoped or compressed form and which becomes deployed or extended in flight in response to some condition being satisfied. An example of this approach is shown in US. Pat. No. 3,388,664.

Although ordnance fuzes utilizing such extension probes generally operate satisfactorily, on occasion they have been found to exhibit a tendency to wobble or oscillate in flight. It was found that as the ordnance device passed through dense foliage, this wobbling or oscillation occasionally will cause the probe to engage a tree limb slightly offset from the line of travel of the ordnance device, and as the ordnance device continued to fall along its line of travel the probe would be bent back by the limb and either broken or permanently bent backwards. To eliminate this objectionable probe and its accompanying problems the probe should be made as rigid as possible. Moreover, such a probe is by nature axially collapsible. To prevent such axial collapse at target impact it is preferable that the probe be locked in its extended configuration. Finally, inertia detonating systems require an abrupt deceleration of the fuze for the inertia detonating system to function properly. Thus, to achieve detonation at the desired standoff distance above target ground the probe must be capable of withstanding the force necessary to decelerate the ordnance device.

SUMMARY OF THE INVENTION Accordingly, one object of this invention is to provide a new and improved fuze for an aerial ordnance device capable of discriminating between foliage and a target composed of solid, loose or soft material.

Another object of the present invention is to provide a new and improved mechanical ordnance fuze actuable on impact with either a soft or hard target, but not foliage, or in the event of an abrupt deceleration.

Another object of the present invention is to provide a new and improved mechanical ordnance fuze actuable a proximate distance above the ground target.

Still another object of this invention is to provide a new and improved mechanical ordnance fuze actuable a proximate distance above the target ground and which is secure against interference with foliage covering the target.

A further object of the instant invention is to provide a new and improved ordnance fuze having desirable safety and arming characteristics.

Briefly, in accordance with the invention, these and other objects are attained by a fuze actuating assembly extendable forwardly of the main fuze body and having a weakened portion rupturable upon impact with a target formed of solid material to affect an explosive ignition and a portion crushable by congestion of loose material of a target composed of such material. The actuating assembly also avoids an explosive ignition by providing shielding from the impact of foliage.

A more complete appreciation of the invention and its many attendant advantages will develop as it becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIGS. la, lb and 1c comprise an elevation sectional view of a fuze according to the invention;

FIG. 2 is another elevation view, partly in section, of the fuze of FIGS. In to 10 rotated FIG. 3 is a section along lines 3-3 of FIG. 1;

FIG. 4 is an elevational view of the clamp and the louvers formed therein in its prefinished form; and,

FIG. 5 is an elevational view of the clamp in its finished form.

Referring now to the drawings wherein like reference characters designate identical or corresponding parts throughout the several views and more particularly to FIGS. la to 3 whereon the ordnance fuze is shown as having a generally cylindrical, tubular casing 10 with an integral annular flange 12 at the rear end thereof by means of which the fuze may be attached to an aerial ordnance device, such as a bomb, projectile or the like by conventional means, such as bolts or the like. The forward end of the fuze casing 10 is closed by a lid 14 crimped into a cannelure 15 formed in the fuze casing 10 at the front end thereof. The lid 14 has attached thereto a tab 16 by which the lid 14 may be wrenched off.

The central axial bore of the fuze casing 10 is stepped at 18 to form a shoulder against which an elongate tubular insert 20 bears. The tubular insert 20 fits somewhat loosely within the bore but is swaged outwardly at intervals around its rearward portion to form radial protrusions 19 which bear snugly against the bore wall to firmly secure the tubular insert 20 in place within the fuze casing 10.

The tubular insert 20 is closed at its rear end by a closure plate 21 which may be made of plastic. Closure plate 21 may be affixed to tubular insert 20 by means of fasteners 17, such as Speed Nuts which grip a plurality of integral lugs 23 extending through corresponding holes in the closure plate 21.

Disposed within the tubular insert 20 and attached thereto by a rivet 22 or the like are clamp 24, to be described more fully hereinafter and an extendable probe 25. Probe 25 is formed of a volute spring, such as the Stacer" made by Hunter Spring Company of Hatfield, Pa. In the telescoped position illustrated, the probe is stressed and requires the axial restraining force supplied by the crimped-on lid 14 to maintain it in that position. When the cover is removed, the probe immediately extends itself forward to its fully relaxed unstressed position. As the probe 25 extends, the diameter of its base or rear portion decreases, and when it is again telescoped, the base diameter again increases.

This change in base diameter between the extended and telescoped positions is utilized to enhance the rigidity and axial strength of the extended probe by exerting a constrictive force around the base of the probe when extended, thereby inhibiting any tendency for the base to expand when the probe is stressed.

For this purpose, constrictive locking clamp 24 surrounds the base of probe 25 to exert a constrictive force therearound, and to lock in the constricted position.

The clamp 24, as more clearly illustrated in FIGS. 4 and 5, is formed of a sheet of resilient material, such as spring steel rolled into a tight spiral. In its relaxed unstressed condition, as illustrated in FIG. 5, clamp 24 forms a tube of approximately 2 /4 overlapping turns of the sheet. As illustrated in FIG. 1a the clamp is attached to tubular insert by rivets 22 and 22' and has been expanded to approximately 1% to 1% turns and is stressed to exert a constrictive force on the probe 25. As best seen in FIG. 4 the clamp 24 has formed therein at least three louvers 26, with two of the three louvers near one end of the material formed to protrude below one surface thereof with the louver edge 27 facing toward the opposite end of the material, and the other of the three louvers formed near the other end of the material and protruding from the opposite surface thereof with its louver edge 28 facing toward the other louvers. The clamp is formed by rolling the material up from the right side to form a tight tube and then treating it, as by heating to relieve the stresses so the position illustrated in FIG. 5 becomes the unstressed configuration. The clamp is then expanded to surround the telescoped probe 25 and, in the expanded position, the louvers of the inner turn are on the other side of the louvers of the outer turn so their sloping sides face each other. When the probe extends, the base thereof reduces in diameter and the clamp correspondingly reduces in diameter causing the louvers of the inner turn and the louver of the outer turn to approach each other. As the clamp diameter continues to decrease, the slope sides of the louvers slide over each other and as the louver edges 27 and 28 pass each other they snap down into an opposed facing relationship thus locking the clamp 24 against any expansion and concomitantly effectively locking the base of the probe at its small diameter. The probe is thereby locked in its extended position and is capable of resisting much greater axial and lateral forces than when its base is not locked at the reduced diameter.

Attached to the inner turn 29 of probe 25 is a fuze actuator assembly generally indicated by the reference numeral 30. Thus, when the probe 25 is extended, the actuator assembly will be mounted on the forward end thereof.

Actuator assembly 30 has a hollow housing 32 with an open rear end 33 and a front end closed but for an aperture 34 formed therethrough. Disposed within the aperture 34 is an electrical contact member 35 having a shoulder 36 of larger diameter than the aperture 34 which prevents the contact member 35 from passing rearwardly through the aperture. An axial contact pin 38, having a flat contact disk 38 fixed to its forward end, extends through and is insulated from contact member 35. At the forward end of pin 38, contact disk 38' makes electrical contact with piezoelectric crystal 44, and the rear end of pin 38 is connected to connector 39. The connector 39 connects the pin 38 to an insulated electrical wire 37 coiled within housing 32, the other end of which is connected to a contact plate 37' attached to closure plate 21 as will be explained more particularly hereinafter.

Abutting against the forward end of the actuator assembly housing 32 is a primer housing assembly 40. The primer housing assembly 40 contains an anvil-shaped member 42 having a forward opening cavity 43 for holding a primer 47 and which is covered by a frangible cover plate 41. Positioned immediately behind the anvil 42 is the piezoelectric crystal 44 insulated from a shell 45 of the primer housing assembly 40 by an insulator ring 46 and from a rear plate 49 of the primer housing assembly 40 by an insulator washer 48. The contact pin 38 extends through a hole formed in the rear plate 49 of the primer housing assembly 40 and physically engages the piezoelectric crystal 44. Thus, when the primer in the primer cavity 43 is detonated, the anvil 42 stresses the piezoelectric crystal 44, thereby inducing a potential difference thereacross which is conducted via contact pin 38 and connector 39 to the insulated wire 37, connected to electrical contact plate 37 the function of which will be explained more fully hereinafter.

Mounted forwardly of and surrounding the primer housing assembly 40 is a foliage discriminator member 50 which includes a base ring 51 connected to a central ring 54 by a relatively weak rupturable or frangible link 52. The inside diameter of the base ring 51 is slightly larger than the outside diameter of the central ring 54 in order that the latter may telescope within the former when an impact is delivered to the foliage discriminator member 50 of a magnitude sufficient to rupture the frangible link 52 therebetween. The base ring 51, frangible link 52 and central ring 54 may be integrally formed as illustrated or may be three separate pieces, with the frangible link in the form of a thin washer having an inside diameter the same as that of the central ring and an outside diameter the same as that of the base ring.

Abutting or integral with and extending laterally across the forward edge of the central ring 54 is a guide plate 55 having a central aperture 56 formed therethrough. Extending around the edge of the guide plate 55 and mounted thereon to project forwardly therefrom is a peripheral foliage fending wall 58 having an internal chamfer 59 around the inside forward edge thereof.

Peripheral foliage fending wall 58 defines a pocket 68 in which is mounted a firing pin support assembly 60 which has an impact transmitting rod 61 slidably mounted in an aperture 56 of guide plate 55. An impact receiving cap 62 is disposed on the forward end of rod 61 and has a diameter substantially larger than that of the rod 61. Connected to the cap 62 is a crush cup 63, the sides 64 of which support the cap a short distance forward of the guide plate 55 as illustrated in FIG. 1a. A shoulder 65 is formed on the rod 61 of a diameter larger than the aperture 56 thereby preventing the rod from forward movement through aperture 56 beyond the position illustrated in FIG. 1a. Rod 61 is provided with a firing pin 66 at the rearward end thereof.

Surrounding the foliage discriminator member 50, the primer housing assembly 40 and the forward portion of the housing 32 is a ferrule 69 having internal peripheral shoulders 69 which correspond to and seat on external peripheral shoulders 57 of the foliage discriminator member 50. The ferrule 69 is crimped onto the housing 32 thereby securing together the component parts of the actuator assembly 30.

A spacer ring 67 includes ferrule 69 somewhat rearward of the front end thereof to prevent undesirable play of the actuator assembly 30 within the interior of the telescoped probe 25.

A resilient bearing plate 53 is positioned between the lid 14 and the discriminator member 50 to provide a biasing force to maintain the probe 25 in fully telescoped position, thereby precluding the possibility of a premature withdrawal of arming pin from its locking position, as will be explained more completely hereinafter.

On fuze impact with a target composed of a soft material such as loose dirt, sand, mud or water, the target material will congest inside the pocket 68 and compress against the cap 62. The force exerted by the congested material on cap 62 will cause the crush cup sides 64 to collapse and rod 61 to be driven rearwardly thereby driving firing pin 66 through the frangible cover 41 into primer 47 to effect detonation thereof.

On the other hand on impact of the fuze with a target composed of hard material, such as stone or armor plate, the force of impact will be transmitted to the frangible link 52 which will rupture, thereby allowing central ring 54 to telescopically slide within base ring 51. The rearward sliding of ring 54 will carry with it guide plate 55 and, because shoulder 65 prevents forward movement of rod 61 relative to guide plate 55, the firing pin 66 is carried rearwardly and driven through the frangible cover 41 to engage and detonate the primes 47.

In turn, an encounter by the fuze with leafy foliage over the target will not produce sufficient force to rupture the frangible link 52, and wall 58 brushes aside or fends off the foliage, thus protecting the cap 62 from impact therewith. Thus, the actuator will not function as it passes through foliage but it will on impact with a target formed of hard, soft or loose material.

A safety and arming assembly 70 is mounted at the rear of fuze casing 10. This assembly includes a mounting block 71 having an integrally formed flange 72 which fits into a corresponding ledge 13 fonned in the inside periphery of flange 12, thereby permitting the rear surface of mounting block 71 to be flush with the rear face of flange l2. Flange 72 has countersunk holes 73 spaced therearound which correspond with threaded holes 11 formed in the fuze casing for receiving screws 74 to secure the mounting block 71 in the fuze casing 10.

Formed in the main body of the mounting block 71 is a central compartment 75, but seen in FIG. 3. The compartment 75 is defined on three sides and the bottom by the mounting block 71 and on the fourth side by the baseplate 87 of a timer assembly 85, FIG. 1c, to be described hereinafter.

An arming rotor 90 is positioned within the compartment 75 and journaled at one end in the timer assembly baseplate 87 and at the other end in a rocket 76 in the mounting block. The rotor 90 has a transverse bore 91 formed therethrough for receiving a detonator 124, but seen in FIG. 2, an axial slot 92 for receiving the arming pin 120, and a tangential notch 98 for engaging a locking shaft 105. A projecting tang 94, seen in FIG. 10, extends from the rotor 90, through a 90 arcuate slot 77 formed in the mounting block 71 concentric with the axis of the rotor 90, and into the bore 78 of the inertia detonating system to be described hereinafter. A torsion spring 95 is positioned about shaft 96 of the rotor, having one end attached to the shaft and the other end attached to the mounting block. The spring 95 biases the rotor 90 in the counterclockwise direction as viewed in FIG. 2 and will rotate it 90 when the rotor is unlocked as will be described hereinafter.

The first or pressure operated safety lock mechanism 100, best seen in FIG. 2, includes a piston 101 having a peripheral groove formed therein to hold an O-ring seal 102. Piston 101 rides in a cylindrical bore 79 formed in the mounting block 71. The bore 79 has a wide diameter portion in which the piston rides, a reduced diameter portion 80 for receiving an O-ring seal 103, and a narrow diameter portion 81 which extends traversely through the mounting block to compartment 75 for receiving locking shaft 105. A small diameter hole is drilled into the wall of bore 79 adjacent the rear face of piston 101 in the forward or locking position shown in FIG. 2. A shear wire 104 is secured in the hole 82 and prevents the premature rearward movement of piston 101.

Attached to and projecting forwardly of piston 101 is the locking shaft 105 having a main locking portion 106 and a short spotting portion 107 of somewhat larger diameter than the former portion. A shoulder 108 formed by the difference in diameters of the two portions is useful for positioning the piston 101 and for holding a washer l 10 in place. Washer 110 has a central aperture 1 1 1 substantially the same as the diameter of the locking portion 106 of the shaft 105 but smaller than that of spotting portion 107 and is positioned in the bore 79 immediately adjacent the reduced position 80 with its central aperture 111 aligned with the narrow portion 81 of bore 79. On assembly, the piston 101 is inserted into the bore 79 until the shoulder 108 abuts against the washer 110, defining between the washer 110 and the front face of piston 101 a pressure chamber 79'. In this assembled position the rear face of piston 101 is adjacent and forward of hole 82 so shear wire 104 may be inserted and secured in place.

The locking shaft 105 is of a length such that when shoulder 108 abuts washer 110, shaft 105 extends through bore 81 and protrudes into compartment 75 engaging the tangential notch 98 formed in the periphery of rotor 90. The locking shaft 105 must be withdrawn from engagement with the tangential rotor notch 98 before the rotor 90 can rotate 90 to its arm position.

The withdrawal of shaft is affected by means of pressure acting in chamber 79 against the front face of piston 101. This pressure is generated by a gas generating pyrotechnic composition 115 positioned in bore 83 communicating with chamber 79'. The gas generating pyrotechnic composition 115 is initiated by an electroresponsive detonator (not shown) in bore 83 and itself initiated by an electrical impulse delivered to an electrical connector 119 via electrical plug 119' (FIG. 3) delivered from an external source. The pressure in chamber 79' generated by composition 115 exerts sufficient force against piston 101 to sever shear wire 104 and pushes piston 101 and locking shaft 105 down through the bore until the piston abuts against the inside wall of the fuze casing 10. The O-ring seals 102 and 103 retain the pressure in the chamber 79' so the piston is prevented from returning to its initial locking position. Moreover, the O-ring seals 102 and 103 exert a frictional force on the piston and shaft which tends to retard a return movement thereof.

As best seen in FIG. 1c, the second or extension actuated, safety lock mechanism 120 includes arming pin 121 which is connected its forward end to the actuator housing 32, extends between the arms of a brace 122 (FIG. 3), and into the axial slot 92 of rotor 90, thereby initially locking the rotor in its unarmed position and preventing rotation thereof. When the extendable probe 25 extends, it carries housing 32 and arming pin 12] with it thereby withdrawing the end of pin 121 from the rotor axial slot 92 and permitting spring 95 to rotate the rotor 90 to its armed position.

As shown in FIG. 10, a timer assembly 85 is mounted on block 71 housing a front plate 86 and a baseplate 87 separated by three spacer rods 114. Mounted on a shaft 116 extending through the baseplate 87 on the bottom side thereof is an input gear 88 which is connected via the shaft and through an amplifying gear train 117 to an escapement mechanism 89 which limits the speed at which input gear 88 turns.

Keyed to rotor shaft 96 is a gear 99 having gear teeth projecting therefrom over an arc of about 45. The input gear 88 is so positioned on the baseplate 87 as to be engaged by the teeth of gear 99 when the rotor is in its safe or unarmed position. When the two safety locks 105 and 121 are withdrawn from their respective locking positions in the rotor notch 98 and slot 92 respectively, spring 95 turns the rotor counterclockwise as viewed in FIG. 2 with the speed of rotation being governed by the escapement mechanism 89 by way of rotor gear 99, input gear 88 and the amplifying gear train 117. When the rotor has rotated approximately 45, the teeth on gear 99 run off input gear 88 and spring 95 snaps the rotor around the remaining 45 to its armed position. The rotor is prevented from rotation beyond its armed position by tang 94 abutting the end of the arcuate slot 77 formed in mounting block 71, which slot extends through a 90 are, thereby permitting rotation of the rotor of only 90.

Referring now to FIG. 2, when the rotor 90 rotates to its armed position, the spring biased contact bottom 123 makes contact with contact plate 37' affixed to closure plate 21 to which electrically insulated wire 37 is connected. A complete electrical circuit is thus established between the piezoelectric crystal 44, contact pin 38, connector 39, wire 37, contact plate 37, contact bottom 123 to the electric initiator 124' of detonator 124.

When rotor 90 is in its armed position detonator 124 is aligned with the channel 84 by way of which the ignition of detonator 124 is conveyed to the detonator of the ordnance device with which the fuze of the instant invention is associated.

If, for some reason, the detonator 124 fails to be initiated by the electrical impulse generated by the piezoelectric crystal 44, the fuze is provided with an auxiliary inertia detonating mechanism 125 consisting of an inertia weight 126 slidably positioned in a bore 78 in block 71 and biased toward the rear of the bore by a coil spring 127.

Inertia weight 126 has two spaced peripheral grooves; one being a narrow groove 128 near the forward end of the weight and the other a wider groove 129 near the rear end thereof. Narrow groove 128 accommodates the rotor tang 94 when the rotor is in its safe or unarmed position and thereby prevents weight 126 from moving forward in the event that the fuze is subjected to an inadvertent impact force, such for example as by being dropped.

An auxiliary L-shaped firing pin 130 is pivotally mounted on a pin 131 and is normally biased away from the rotor 90 by a spring 132 mounted on pin 131. The firing pin 130 is bent 90 toward the rotor 90 and sharpened to a point 133. Projecting below the firing pin 130 and into the wide groove 129 in a cam 134 having a sloping side facing the rear edge of the wide groove 129.

When the rotor 90 is in its armed position, the point 133 of firing pin 130 is aligned with an auxiliary primer (not shown) located in the side of rotor 90, and rotor tang 94 has rotated with the rotor out of the narrow groove 128. Upon impact, the

inertia force acting on weight 126 will overcome the restraining force being exerted thereon by spring 127 and weight 126 will ride forward, compressing spring 127. The rear edge of groove 129 will stroke cam 134 causing firing pin 130 to pivot about pin 131 thereby driving firing pin point 133 into engagement with the auxiliary primer. Detonation of the auxiliary primer affects detonation of the detonator 124. Since a moderately high impact is required to cause the auxiliary detonating mechanism 125 to function, the extendable probe 25 must be sufficiently strong to withstand this impact to secure detonation with the desired standoff above the target.

operationally, when the fuze and its associated ordnance device is released from it launching vehicle, such as an aircraft or a rocket, an electrical signal from the launching vehicle is applied to detonator 1 18 via electrical connector 1 19, thereby initiating gas generating composition 115. The pressure developed by gas generating composition 115 acts against piston 101 causing withdrawal of locking shaft 105 from notch 98 of rotor 90. With the lid 14 is wrenched off, as by a wire connected between the launch vehicle and the lid tab 16, the extendable probe 25 extends, carrying with it actuator assembly 30 and arming pin 121. This action withdraws arming pin 121 from slot 92 of rotor 90 thereby releasing the rotor from its initial unarmed condition to be rotated 90 under the influence of spring 95 to its armed position.

The probe extends to its full length, being restrained from undue extension by a nylon tether 113, and is locked in its extended position by locking clamp 24.

As the fused aerial ordnance device approaches its hard or soft target, the forward orientation of the probe is maintained by a conventional retardation device on the rear of the device. As hereinbefore disclosed the actuator 30 passes uneffected through any foliage encountered and functions on impact with the target to affect detonation of the ordnance device a proximate distance above the target.

Obviously, numerous variations and modifications of the above described best mode or preferred embodiment of the invention, defined by the appended claims, may be made.

What is claimed as new and desired to be secured by Letters Patent is:

1. [n a fuze for an aerial ordnance device, a fuze actuating means comprising:

forwardly projecting circumferentially disposed means for fending off foliage encountered in the path of the device over the target, said fending means defining a forwardly opening pocket;

a firing pin;

a primer operatively aligned with said firing pin;

impact receiving means operatively connected to one of said primer and firing pin for affecting forceful engagement of said firing pin and said primer upon impact with said impact receiving means;

said impact receiving means having portions thereof located within said pocket, movable therewith, and frangibly supported rearward of the forward opening thereof by frangible support means;

mounting means for supporting said fending means including a weak portion rupturable upon impact of said fending means with a hard target;

whereby foliage encountered in the path of the device will be fended off and prevented from impinging against said impact receiving means, and impact of said fending means with a soft or loose material will cause said material to be gathered and congested within said pocket against said impact receiving means, causing rearward movement thereof and affecting engagement of said primer and said firing pin, and impact of said fending means with a hard or solid target will cause the rupture of said weak portion thereby causing rearward movement of said impact receiving mean and affecting engagement of said primer and said firing pin.

2. Apparatus according to claim 1 wherein:

said fending means further comprises means for slidably guiding the rearward movement of said impact receiving means on impact with said materials, said guide means comprising a plate having means defining an aperture therethrough,

said impact receiving means being slidably disposed within said aperture, and comprising a rod and a cap affixed to the forward end of said rod,

said plate defining the rear terminus of said pocket;

said firing pin being attached to the rearward end of said impact receiving means;

said primer being mounted to the rear of and adjacent to said firing pin;

said frangible support means comprising a crush cup having sidewalls contacting said plate and a bottom wall affixed to said cap;

whereby said crush cap restrains said impact receiving means in its forward position before impact with said materials, but at said impact said materials are congested within said pocket against said cap whereat said crush cap sidewalls and bottom collapse and allow said impact receiving means to be impelled rearwardly by said material.

3. Apparatus according to claim 1 further including:

means extendable forwardly from the ordnance device for positioning said actuating means a proximate distance forward of said device;

4. Apparatus according to claim 3 wherein said extendable means comprises:

an extendable probe comprising a volute spring which is extended in the relaxed, unstressed condition thereof and which is stressed in the telescoped condition, thereof whereby said probe tends to assume the extended configuration,

said actuating means being attached to the forward end of said probe and said probe being attached at the rearward end thereof to said fuze.

5. Apparatus according to claim 3 further comprising:

locking means connected to said extendable means for locking said extendable means in the extended position thereof.

6. The device of claim 4, further comprising: clamp means for exerting a constrictive force about the rearward end of said probe, said clamp means having at least one partly overlapping loop of resilient sheet material disposed around the outside turn of said probe when said probe is in the collapsed condition thereof, said loop being biased to exert an inward, constrictive force on said probe, said clamp means having at least one set of locking louvers comprising at least two aligned louvers formed in said resilient material to protrude from opposite sides thereof and having the louver edges facing toward each other, whereby when the clamp is allowed to contract the inclines of the louver sides will slide over each other until the louver edges pass each other, than any radial expansion of said loop is prevented by the abutting louver edges.

7. Apparatus according to claim 6 wherein:

said fending means further comprises means for slidably guiding the rearward movement of said impact receiving means on impact with said materials, said guide means comprising a plate having means defining an aperture therethrough,

said impact receiving means being slidably disposed within said aperture, and comprising a rod and a cap affixed to the forward end of said rod,

said plate defining the rear terminus of said pocket;

said firing pin being attached to the rearward end of said impact receiving means;

said primer being mounted to the rear of and adjacent to said firing pin;

said frangible support means comprising a crush cup having sidewalls contacting said plate and a bottom wall affixed to said cap;

whereby said crush cup restrains said impact receiving means in its forward position before impact with said materials, but at said impact said materials are congested within said pocket against said cap whereat said crush cap sidewalls and bottom collapses and allow said impact receiving means to be impelled rearwardly by said materials.

8. Apparatus according to claim 3 further comprising:

a safety and arming mechanism having arming means movable between a safe position and an armed position,

extension actuated locking means connected to the forward end of said extendable means for locking said arming means in said safe position whereby, when said extendable means extends the forward end thereof carries said locking means forward thereby unlocking said arming means.

9. Apparatus according to claim 8 further comprising:

pressure actuated locking means for locking said arming means in said safe position including means for generating a fluid pressure,

movable means shiftable under the influence of said pressure, means for directing said fluid pressure against said movable means, and means connected to said movable means for preventing the movement of said arming means to armed position until said movable means is shifted by said fluid pressure.

10. Apparatus according to claim 6 further comprising:

said fending means further comprises means for slidably guiding the rearward movement of said impact receiving means on impact with said materials, said guide means comprising a plate having means defining an aperture therethrough,

said impact receiving means being slidably disposed within said aperture, and comprising a rod and a cap affixed to the forward end of said rod,

said plate defining the rear terminus of said pocket;

said firing pin being attached to the rearward end of said impact receiving means;

said primer being mounted to the rear of and adjacent to said firing pin;

said frangible support means comprising a crush cap having sidewalls contacting said plate and a bottom wall affixed to said cap;

whereby said crush cap restrains said impact receiving means in its forward position before impact with said materials, but at said impact said materials are congested within said pocket against said cap whereat said crush cap sidewalls and bottom collapse and allow said impact receiving means to be impelled rearwardly by said materials. 

1. In a fuze for an aerial ordnance device, a fuze actuating means comprising: forwardly projecting circumferentially disposed means for fending off foliage encountered in the path of the device over the target, said fending means defining a forwardly opening pocket; a firing pin; a primer operatively aligned with said firing pin; impact receiving means operatively connected to one of said primer and firing pin for affecting forceful engagement of said firing pin and said primer upon impact with said impact receiving means; said impact receiving means having portions thereof located within said pocket, movable therewith, and frangibly supported rearward of the forward opening thereof by frangible support means; mounting means for supporting said fending means including a weak portion rupturable upon impact of said fending means with a hard target; whereby foliage encountered in the path of the device will be fended off and prevented from impinging against said impact receiving means, and impact of said fending means with a soft or loose material will cause said material to be gathered and congested within said pocket against said impact receiving means, causing rearward movement thereof and affecting engagement of said primer and said firing pin, and impact of said fending means with a hard or solid target will cause the rupture of said weak portion thereby causing rearward movement of said impact receiving mean and affecting engagement of said primer and said firing pin.
 2. Apparatus according to claim 1 wherein: said fending means further comprises means for slidably guiding the rearward movement of said impact receiving means on impact with said materials, said guide means comprising a plate having means defining an aperture therethrough, said impact receiving means being slidably disposed within said aperture, and comprising a rod and a cap affixed to the forward end of said rod, said plate defining the rear terminus of said pocket; said firing pin being attached to the rearward end of said impact receiving means; said primer being mounted to the rear of and adjacent to said firing pin; said frangible support means comprising a crush cup having sidewalls contacting said plate and a bottom wall affixed to said cap; whereby said crush cap restrains said impact receiving means in its forward position before impact with said materials, but at said impact said materials are congested within said pocket against said cap whereat said crush cap sidewalls and bottom collapse and allow said impact receiving means to be impelled rearwardly by said material.
 3. Apparatus according to claim 1 further including: means extendable forwardly from the ordnance device for positioning said actuating means a proximate distance forward of said device;
 4. Apparatus according to claim 3 wherein said extendable means comprises: an extendable probe comprising a volute spring which is extended in the relaxed, unstressed condition thereof and which is stressed in the telescoped condition, thereof whereby said probe tends to assume the extended configuration, said actuating means being attached to the forward end of said probe and said probe being attached at the rearward end thereof to said fuze.
 5. Apparatus according to claim 3 further comprising: locking means connected to said extendable means for locking said extendable means in the extended position thereof.
 6. The device of claim 4, further comprising: clamp means for exerting a constrictive force about the rearward end of said probe, said clamp means having at least one partly overlapping loop of resilient sheet material disposed around the outside turn of said probe when said probe is in the collapsed condition thereof, said loop being biased to exert an inward, constrictive force on said probe, said clamp means having at least one set of locking louvers comprising at least two aligned louvers formed in said resilient material to protrude from opposite sides thereof and having the louver edges facing toward each other, whereby when the clamp is allowed to contract the inclines of the louver sides will slide over each other until the louver edges pass each other, than any radial expansion of said loop is prevented by the abutting louver edges.
 7. Apparatus according to claim 6 wherein: said fending means further comprises means for slidably guiding the rearward movement of said impact receiving means on impact with said materials, said guide means comprising a plate having means defining an aperture therethrough, said impact receiving means being slidably disposed within said aperture, and comprising a rod and a cap affixed to the forward end of said rod, said plate defining the rear terminus of said pocket; said firing pin being attached to the rearward end of said impact receiving means; said primer being mounted to the rear of and adjacent to said firing pin; said frangible support means comprising a crush cup having sidewalls contacting said plate and a bottom wall affixed to said cap; whereby said crush cup restrains said impact receiving means in its forward position before impact with said materials, but at said impact said materials are congested within said pocket against said cap whereat said crush cap sidewalls and bottom collapses and allow said impact receiving means to be impelled rearwardly by said materials.
 8. Apparatus according to claim 3 further comprising: a safety and arming mechanism having arming means movable between a safe position and an armed position, extension actuated locking means connected to the forward end of said extendable means for locking said arming means in said safe position whereby, when said extendable means extends the forward end thereof carries said locking means forward thereby unlocking said arming means.
 9. Apparatus according to claim 8 further comprising: pressure actuated locking means for locking said arMing means in said safe position including means for generating a fluid pressure, movable means shiftable under the influence of said pressure, means for directing said fluid pressure against said movable means, and means connected to said movable means for preventing the movement of said arming means to armed position until said movable means is shifted by said fluid pressure.
 10. Apparatus according to claim 6 further comprising: said fending means further comprises means for slidably guiding the rearward movement of said impact receiving means on impact with said materials, said guide means comprising a plate having means defining an aperture therethrough, said impact receiving means being slidably disposed within said aperture, and comprising a rod and a cap affixed to the forward end of said rod, said plate defining the rear terminus of said pocket; said firing pin being attached to the rearward end of said impact receiving means; said primer being mounted to the rear of and adjacent to said firing pin; said frangible support means comprising a crush cap having sidewalls contacting said plate and a bottom wall affixed to said cap; whereby said crush cap restrains said impact receiving means in its forward position before impact with said materials, but at said impact said materials are congested within said pocket against said cap whereat said crush cap sidewalls and bottom collapse and allow said impact receiving means to be impelled rearwardly by said materials. 